The aim of the present work was studied the influence of both the chemical composition and the post heat
treatment on the wear resistance of composite coatings deposited by using HVOF JP-5000 gun onto AISI 1020
steel substrate. For such a purpose, prior to deposition, the NiCrBSiWFe alloy powder was mechanically mixed
with different amounts of WC-12%Co powder in order to conform three coatings having the following
composition: 100% NiCrBSi; 50%NiCrBSi + 50 % (WC-12%Co) and 30% NiCrBSi +70 % (WC-12%Co). An
oxyacetylene flame was used to perform the post heat treatment, whose duration was of 300 seconds. The
evaluation of the wear resistance of these coatings was achieved by means of abrasion wear tests according to
ASTM G65-C. The hardness of the coating was determined by means of Vickers indentation using a load of 300
g. A detailed study of the wear track was carried out by Scanning Electron Microscopy (SEM) combined with
Energy Dispersive X-ray microanalysis (EDX) in order to provide information of the wear mechanisms. The
results have shown that the wear resistance increases with the increase of the WC-Co amount in the powder
mixture. However, this increase is more significant once the post heat treatment was performed, as consequence
to both the precipitation hardening, which takes place in the nickel matrix ensuring a more uniform particles
distribution, and to a considerable decrease in the porosity.
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